Squeezed spectra for mass-shifted fermions

The interaction between particles and their surrounding medium can induce a squeezing effect. The impacts of squeezing effect on the transverse momentum spectra of fermions and anti-fermions are studied. The squeezing effect reduces the slope of transverse momentum spectra for both proton and anti-proton. When protons have a nonzero chemical potential, this effect affects the proton and anti-proton differently. It also results in a higher yield of both proton and anti-proton, especially noticeable at higher transverse momentum values for anti-proton. Consequently, the yield ratio [Formula: see text] increases with rising transverse momentum, eventually approaching 1. Comparison between simulation and experimental data indicates that in-medium mass modification for proton and anti-proton occurs primarily in low momentum regions ([Formula: see text] [Formula: see text]GeV/c) in Au+Au collisions at [Formula: see text] [Formula: see text]GeV and [Formula: see text] [Formula: see text]GeV, with the in-medium mass-shift ranging from 0 to several tens of MeV. Additionally, as the freeze-out temperature and collision energy increase, the upper limit of the in-medium mass-shift slightly increases. This paper’s study may offer a fresh approach to examine the in-medium characteristics of fermions and anti-fermions.